All the body’s attributes change with age, and
mental functions are no exception. Memory is the most
fragile mental function. With age, new learning is slower,
new information is processed less carefully, and details
often slip. These changes give rise to the “senior
moment” in healthy elders and to cognitive impairment
and dementia in others.

Testosterone levels decline with age, just when memory
begins to slow. Might falling hormone levels account for
some of the problem? Perhaps, says Harvard Men’s
Health Watch. The data are far from conclusive, but studies
have found some connections. For instance, higher testosterone
levels in midlife have been linked to better preservation
of tissue in some parts of the brain. And in older men,
higher testosterone levels have been associated with better
performance on cognitive tests.

If higher testosterone levels are associated with better
mental function, do treatments that reduce testosterone
lead to cognitive decline? Three studies linked impaired
performance on cognitive tests with androgen deprivation
therapy, which is sometimes used in treating prostate
cancer. However, the effects were modest and certainly
should not deter men from receiving this treatment if
needed.

This research also raises the question of whether testosterone
therapy might improve mental function in healthy older
men, or even in those with cognitive impairment. Only
a few small, short-term studies have examined this, and
some have reported subtle improvements on cognitive tests.
However, high testosterone levels may have harmful effects
as well. Harvard Men’s Health Watch suggests that
until more research findings are available, men should
not use testosterone or any other androgen to improve
mental function.